In a digital display system, such as a digital map system in an avionic cockpit environment, symbols representing aeronautical data, such as waypoints, are usually overlayed over an aeronautical chart or other display background. FIG. shows a typical cockpit display 10 including symbols 12, 14 and 16. Such displays, including the symbology, are typically generated from data received from an onboard computer such as a digital map computer, for example. Such display systems must meet stringent requirements, such as updating the display up to 60 times per second, and this leads to limitations on the number of symbols which can be displayed at any given point in time. If such a system attempts to display too many symbols simultaneously, an excess data condition can arise which results in dimming and ultimately flickering of the display. This is because prior display systems did not have the capability to reduce symbology when an excess data condition existed. Such prior art display systems extended the stroke time to accommodate all symbols rather than adaptively limiting the number of symbols to fit a fixed stroke time. Stroke time is defined as the time it takes to accomplish stroke scanning of all the symbols. Current display systems have fixed refresh period requirements which allow only a limited stroke time period between refresh cycles. In prior art systems which had non-fixed stroke times, when more stroke time was used to accommodate an increasing number of symbols, a longer refresh period resulted. The longer refresh period lead to flickering and dimming of the overall display as viewed by a human observer.